async function getAccessToken(callback) {
  try {
    const resp = await fetch("/api/auth/token");
    if (!resp.ok) {
      throw new Error(await resp.text());
    }
    const { access_token, expires_in } = await resp.json();
    callback(access_token, expires_in);
  } catch (err) {
    alert("Could not obtain access token. See the console for more details.");
    console.error(err);
  }
}

export function initViewer(container, urns) {
  const viewerOptions = {
    extensions: [],
  };

  Autodesk.Viewing.Initializer(
    { env: "AutodeskProduction", getAccessToken },
    () => {
      var viewer = new Autodesk.Viewing.Private.GuiViewer3D(
        container,
        viewerOptions
      );
      viewer.start();
      viewer.addEventListener(
          Autodesk.Viewing.TOOLBAR_CREATED_EVENT,
          onToolbarCreated
        );
      urns.map((m) => {
        addViewable(viewer, m);
      });
    }
  );
}

async function addViewable(viewer, urn, xform, offset) {
  return new Promise(function (resolve, reject) {
    function onDocumentLoadSuccess(doc) {
      const viewable = doc.getRoot().getDefaultGeometry();
      const options = {
        //preserveView: true,
        keepCurrentModels: true,
        modelSpace: true,    // 2D drawings
        applyRefPoint: true, // 3D shared coordinates
        applyScaling: 'm',   // force all models to same scale
        globalOffset: {x:0,y:0,z:0},  // force all models to origin
        //placementTransform: (new THREE.Matrix4()).setPosition(m.xform)
      };
      if (xform) {
        options.placementTransform = xform;
      }
      if (offset) {
        options.globalOffset = offset;
      }
      viewer
        .loadDocumentNode(doc, viewable, options)
        .then(resolve)
        .catch(reject)
      // .then(onToolbarCreated(viewer));
    }
    function onDocumentLoadFailure(code) {
      console.error(`Document load failed with error code: ${code}`);
      console.error(`Failed URN: ${urn}`);
     // console.error(`Access Token: ${accessToken}`); // Log the access token if possible
      reject(`Could not load document (${code}).`);
    }
    console.log(urn);
    Autodesk.Viewing.Document.load(
      "urn:" + urn,
      onDocumentLoadSuccess,
      onDocumentLoadFailure
    );
  });
}

const onToolbarCreated = (e) => {
  const group = viewer.toolbar.getControl("settingsTools");
  group.removeControl("toolbar-modelStructureTool");
  group.removeControl("toolbar-propertiesTool");
  //group.removeControl('toolbar-settingsTool');
  //group.removeControl('toolbar-fullscreenTool');
  viewer.removeEventListener(
    Autodesk.Viewing.TOOLBAR_CREATED_EVENT,
    onToolbarCreated
  );
};